SA9109B

sames

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5.

Tariff Registers

A multiple tariff facility is provided on-chip by means of 4 tariff registers, which are

externally selectable via the SR[0] and SR[1] inputs. The registers may be selected

by programming the SR[0] and SR[1] inputs as follows:

SR[1]

SR[0]

Register

0

0

Register 1

0

1

Register 2

1

0

Register 3

1

1

Register 4

The 4 Tariff registers and Total register may be sequentially displayed by activating

the Push Button (PB). The minimum push button make time is 5ms. The contents

of the register selected for display is retained on the display for a period of 10

seconds, provided that the push button is not activated during this period. After the

10 seconds has elapsed, the display defaults to the "active" register defined by the

status of the SR[0] and SR[1] inputs.

The register selected for display via the push button (PB) is indicated by the

relevant announciators.

6.

Optical Interface

The SA9109B device contains an interface for automatic meter reading, according

to the IEC1107 Mode D standard. The IEC1107 Mode D is a single baud rate of

2400. For the optical interface protocol, the 4-bit words are converted to 8-bit words

(ASCII-format).

After initiation of a serial transmission by pulling PB (pin 34) low, the data format

transmitted on SDO is given below:

Code

Description

/

Start transmission

XXX

ID

3

Baud rate identification

YYYYYYYY

ID

<cr><lf><cr><lf>

Data header

0(nnnnnnnn)

1(nnnnnnnn)

Data of Reg. 2

2(nnnnnnnn)

Data of Reg. 3

3(nnnnnnnn)

Data of Reg. 4

4(nnnnnnnn)

Data of Reg. 'Total' = Sum of registers 0 to 3

!<cr><lf><cr><lf>

End transmission